Finished phase 1

docs/subsystems/RenderEngine.md

@@ -2,7 +2,7 @@
 
 This document expands the `RenderEngine` portion of [PHASE_1_SUBSYSTEM_BOUNDARIES_DESIGN.md](/c:/Users/Aiden/Documents/GitHub/video-shader-toys/docs/PHASE_1_SUBSYSTEM_BOUNDARIES_DESIGN.md). It defines the target ownership, boundaries, and migration shape for the rendering subsystem so later phases can move GL work out of today's mixed orchestration paths without inventing new boundaries on the fly.
 
-The intent here is not to force a one-step rewrite. It is to make the target render boundary explicit enough that later work on events, `RuntimeHost` splitting, and backend decoupling all land in the same place.
+The intent here is not to force a one-step rewrite. It is to make the target render boundary explicit enough that later work on events, live-state layering, sole-owner GL threading, and backend decoupling all land in the same place.
 
 ## Purpose
 
@@ -400,11 +400,11 @@ As new features are added, keep:
 - render-local overlays
 - preview state
 
-inside render-owned code paths instead of putting them back into `RuntimeHost` or service layers.
+inside render-owned code paths instead of putting them back into runtime storage or service layers.
 
 ### Step 3. Isolate Snapshot Consumption
 
-Introduce snapshot-facing APIs so render no longer depends on broad `RuntimeHost` state access for frame production.
+Introduce snapshot-facing APIs so render no longer depends on broad runtime-state access for frame production.
 
 ### Step 4. Move Uploads Onto Render Ownership